Coupling



FIG. 1 is a front perspective view of a coupling;

FIG. 2 is a rear perspective view of the coupling of FIG. 1;

FIG. 3 is front view of the coupling of FIG. 1;

FIG. 4 is rear view of the coupling of FIG. 1;

FIG. 5 is a left-side view of the coupling of FIG. 1;

FIG. 6 is a right-side view of the coupling of FIG. 1;

FIG. 7 is a top view of the coupling of FIG. 1; and,

FIG. 8 is a bottom view of the coupling of FIG. 1.

The broken lines in the drawings illustrate portions of the coupling and form no part of the claimed design. 

CLAIM The ornamental design for a coupling, as shown and described. 